The invention relates to a method for determining the time mean value of a measured quantity as a function of its period of operation. The invention is particularly related to a method for generating a signal responsive to the exceeding of specified pairs of values of mean and period of operation of the measured quantity.
Such a method is, for example, necessary in the monitoring of automatically operating telecommunications exchange equipment. The quantity to be measured may be, for example, error frequency and the specified pairs of values of mean and period of operation of the quantity to be measured are, for example, limiting values. It may be the case that the device being monitored must be shut off and, if necessary, replaced by another device of the same type, when such limiting values are exceeded.
It is known that to determine the time mean of a quantity to be measured, that amount, or an amount proportional to it, is connected to the input of an integrator. The time integral of the quantity to be measured delivered at the output of the integrator is then divided by the period of operation, i.e., the duration of the integration interval. The quotient is the desired time mean of the quantity to be measured. If the determination of the time mean is a function of different values of the integration interval, then the formation of the quotient must proceed continuously between time integral and integration interval. From this discussion, it becomes obvious that a substantial financial outlay for apparatus is necessary, which outlay is increased further in that the continuous formation of a quotient is generated (e.g., a switching command to a replacement circuit for the device being monitored) must be compared with the specified value pairs, in particular, a continuous curve connecting these value pairs.
It is an object of the invention to provide a method for determining the time mean of a quantity being measured as a function of its period of operation.
It is a further object of this invention to provide a method for generating a signal responsive to the exceeding of specified value pairs of mean and duration of operation of the quantity being measured.